Are there any security concerns to be aware of when handling payment information in a PHP-based seat reservation system?

Security concerns when handling payment information in a PHP-based seat reservation system include protecting sensitive data such as credit card details, ensuring secure communication over HTTPS, and implementing proper input validation to prevent SQL injection attacks. One way to address these concerns is by using a secure payment gateway for processing transactions and encrypting payment data before storing it in the database.

// Example of encrypting payment data before storing it in the database
$paymentData = encrypt($creditCardNumber, $encryptionKey);

// Example of decrypting payment data when retrieving it from the database
$decryptedCreditCardNumber = decrypt($paymentData, $encryptionKey);